• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.6
• /
• pp.795-800
• /
• 1985

The ideal Brayton cycle has been analyzed with the heat exchange processes between the working fluid and the heat source and the sink while their heat capacity rates are constant. The power fo the cycle can be expressed in terms of a temperature of the cycle and the heat capacity rate of the working fluid. There exists an optimum power condition where the heat capacity rate of the working fluid has a value between those of the heat source and the heat sink, and the cycle efficiency is determined by the inlet temperatures of the heat source and the sink.

• KSTLE International Journal
• /
• v.1 no.2
• /
• pp.107-112
• /
• 2000

In case of the limitation of Deep RIE fabrication far Micro Gas Turbine, bearing aspect ratio is limited in very small value. The characteristics such as pressure distribution, load capacity and non-linearity of a short bearing of L/D=0.083 and a conventional bearing of L/D=1.0 with coupled boundary effects are investigated for Micro Gas Turbine bearings. The coupled effect was analyzed by mass conservation at coupled end area. The results, increasing load capacity and non-linearity due to the coupled effect of thrust and journal bearing, are obtained and the selection of journal bearing type is discussed.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.198-201
• /
• 2000

The capacity of micelle formation between astaxanthin and various surfactants was compared. Tween 20 was identified the most suitable surfactant in terms of astaxanthin extraction capacity. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effect of micelle formation condition, such as molar ratio of astaxanthin and Tween 20, pH and ionic strength was also investigated. pH and ionic strength showed no significant effects. Antioxidant activity of astaxanthin was twice of ${\alpha}-tocopherol$ and 4 times of ${\beta} -carotene$. Crude astaxanthin extract from the yeast cell seemed to be less degraded than pure astaxanthin by air and light exposure, probably because of the presence of other carotenoids and lipids. Under the optimal conditions, the molar ratio of micelle formed was found to be 1 : 12 for astaxanthin : Tween 20.

• Advances in nano research
• /
• v.3 no.1
• /
• pp.49-54
• /
• 2015

The structure represents symmetrical metal electrode (gate 1) - front $SiO_2$ layer - n-Si nanowire FET - buried $SiO_2$ layer - metal electrode (gate 2). At the symmetrical gate voltages high conductive regions near the gate 1 - front $SiO_2$ and gate 2 - buried $SiO_2$ interfaces correspondingly, and low conductive region in the central region of the NW are formed. Possibilities of applications of nanosize FETs at the deep inversion and depletion as a distributed capacitance are demonstrated. Capacity density is an order to ${\sim}{\mu}F/cm^2$. The charge density, it distribution and capacity value in the nanowire can be controlled by a small changes in the gate voltages. at the non-symmetrical gate voltages high conductive regions will move to corresponding interfaces and low conductive region will modulate non-symmetrically. In this case source-drain current of the FET will redistributed and change current way. This gives opportunity to investigate surface and bulk transport processes in the nanosize inversion channel.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.09a
• /
• pp.189-196
• /
• 2002

The capacity of CFS piers has not been used to a practical design, because there is no guide of a seismic design for CFS piers. Therefore, the guide of a seismic design value is derived from tests of CFS piers in order to apply it to a practical seismic design. Steel piers and concrete-filled steel piers are tested with constant axial load using quasi-static cyclic lateral load to check ductile capacity and using the real Kobe ground motion of pseudo-dynamic test to verify seismic performance. The results prove that CFS piers have more satisfactory ductility and strength than steel piers and relatively large hysteretic damping in dynamic behaviors. The seismic performance of steel and CFS piers is quantified on the basis of the test results. These results are evaluated through comparison of both the response modification factor method by elastic response spectrum and the performance-based design method by capacity spectrum and demand spectrum using effective viscous damping. The response modification factor of CFS piers is presented to apply in seismic design on a basis of this evaluation for a seismic performance.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.615-620
• /
• 2005

The purpose of this study was to provide a criterion of ballast aggregate size distribution for paved track. The parameters considered in this study were different types of particle size distribution. Then the analysis for analyzing compressive and flexural strength, physical characteristics of aggregate, and the ballast box test were performed. In the test result of the physical characteristic performed by the ballast box test, the bearing capacity was measured lower than the expected value because of its boundary conditions. Among four types of ballast aggregate, type B was selected as one of best candidate distribution because of its bearing capacity, strength, development and economics.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.371-378
• /
• 2001

The working load at pile is sometimes subjected to not only compression load but also lateral load and uplift forces. Pile foundation is essential and uplift load can be applied because of buoyancy, a typhoon, wind or seismic forces. This study was carried out to determine the uplift capacity of concrete pile foundation driven in clay. Pile was driven in clay, between pile and clay adhesion factor was estimated, and it is the mean value between the cast-in-situ-pile and steel pipe pile. When pile foundation is loaded for long time, creep behavior occurs. The behavior of creep is originated from the clay creep contacted with pile. The creep behavior of pile foundation embedded in clay is heavily depended on the thickness of clay around the pile shaft, pore water pressure in clay, and creep behavior of clay.

• Computers and Concrete
• /
• v.14 no.1
• /
• pp.59-71
• /
• 2014

The paper is concerned with the analytical description of a resistance mechanism, not considered in previous models, by which the hoops contribute to the shear capacity of RC columns with circular cross sections. The difference from previous approaches consists in observing that, because of deformation, the hoops change their original shape and, as a consequence, their slope does not match anymore the original one in the neighborhood of a crack. The model involves two parameters only, namely the crack inclination and the hoop strain in the neighborhood of a crack. A closed-form analytical formulation to correlate the average value of the crack width and the hoop strain is also provided. Results obtained using the proposed model have been compared with experimental data, and a satisfactory agreement is found.

• Journal of Korean Society of Steel Construction
• /
• v.13 no.6
• /
• pp.641-649
• /
• 2001

It is proposed in this paper the practical load carrying capacity formula for web crippling in trapezoidal sheeting (deckplate). The parameter functions are derived by investigation of the major parameters influencing of load carrying capacity based on the existing theoretical research with experiment analogical interpretation model. The simple strength formula is proposed in analytic comparison of each parameters with the existing experimental data. From statistical evaluations due to Annex Z of Eurocode 3 the partial safety resistance factors ${\gamma}_M$ are calculated and compared with the target value of 1.1.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.273-276
• /
• 2008

As the rapid and various changing of social aspects, the structures are getting bigger, higher and more complex. The importance of evacuation is on the rise as increased using frequency of multiplex sale facility and it's high population density. According to the result of a survey with 4 domestic wholesales mart's population density, the average and maximum was 0.41(人/$m^2$) and 0.46(人/$m^2$). considering evacuation dangerousness, the maximum value will be suitable for computation of evacuation capacity and this will be submitted as a basic data for computation of evacuation capacity.